Experts tackle readers’ garden questions.
Q: Our brother-in-law gave us a seed packet from a national park in Montana. We broadcast the seeds in our garden but one plant has come up that is not identified in the seed packet. Attached are photos after some pruning so it doesn’t look its usual “Audrey II” self. The plant started the first season as a rosette pattern of leaves hugging the ground. Then, this spring it sent up a tall center spike with many side spikes. When I prune it, it makes more spikes. Each spike has yellow flowers that last about a day. No fragrance. The plant has taken over an entire area of the garden, at least a 5-foot diameter space. Can you identify this plant?
Nancy MacKenzie, Sacramento
Bee garden writer Debbie Arrington: That’s an evening primrose, a wildflower that reminds many gardeners of the alien flora Audrey II in “Little Shop of Horrors.” This plant doesn’t eat people but it can swallow up a whole garden.
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There are several species of evening primrose, which is native to North America. By your photo and description, it’s most likely Common Evening Primrose (Oenothera biennis), a familiar wildflower throughout most of the eastern United States. It has several other nicknames including evening star, sun drop and King’s cure-all, reflecting its use as a medicinal herb. Evening primrose oil is still sold as a dietary supplement.
I had some in a wildflower mix I planted several years ago. Our family nicknamed it the octopus plant because of its long “arms” of flowers. This plant can tolerate low water conditions, making it a star in drought-tolerant gardens. But when it gets “normal” irrigation, it grows rapidly into a thug, squeezing out neighboring plants.
As you described, this evening primrose is a biennial, which means its life cycle needs two years to complete. The first year, a rosette of leaves grows close to the ground. The next spring, it starts sprouting tall flower spikes that can reach 5 feet tall. More flower spikes reach out from the sides.
A favorite of bees, butterflies and moths, the flowers open late in the afternoon or early evening, but last only until the next morning, withering by noon. It starts producing flowers in late spring and keeps going through September.
It reseeds profusely. So, if you don’t want a yard full of little Audreys, pull the mother plant before its seed pods dry and scatter seed.
The Bee’s Debbie Arrington is a consulting rosarian and lifelong gardener. @debarrington, 916-321-1075.
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